>> However I don't think I'll copy this strange behaviour (at least not by >> default). As reported by Eric, it breaks programs like JAM (the point >> is, >> even on FAT12 and FAT16 disks) which look into the SFT to get the first >> cluster of a (FAT12 or FAT16) file. > > Whether you call it strange depends... I just call it a change in > layout, just like one was made from DOS 3.3x to DOS 4.
It was however not documented (well, like most things about MS-DOS 7+) and unexpected, especially because the usage of these fields (or their lower word parts) is now incompatible to previous versions even on FAT12/16 filesystems. (Ignoring the fact that it apparently broke SHARE.EXE, too.) > It's hard to be compatible to everyone... In any case JAM can be made > compatible to MSDOS 7.10 on FAT16 by DEBUG > (in addition to the changes discussed before): > debug jmount.com > edf3 > 35 > w > That'll make jmount incompatible with MSDOS<4, DRDOS 5&6, but > compatible with newer versions, because the word at 35h is the last > accessed cluster, and after reading one sector (as Eric showed) that > will still be the starting cluster. Does JAM read anything from the archive file (I presume it wants the first cluster of that file) before looking into the SFT? Also, what if it read exactly one sector (or more) but the cluster size was only one sector, either? Then it would read the second cluster instead of the first one from the SFT. I wouldn't patch the program like that if I didn't know for sure such things wouldn't happen. > It won't help FreeDOS of course because it still uses fnodes for these > things instead of SFTs. Doesn't it update the SFT relative and absolute current cluster values, too? As far as I've understood it, fnodes should be invalidated when leaving DOS, so if these cluster references were saved in the fnode only, it wouldn't help a lot. Regards, Christian ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Freedos-kernel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freedos-kernel
